Great point here Brad...
I think most people don't realize this, because they never actually sit down and try to recollect all the information they hold within their mine...
I believe if people just tried to access the information within their mind, they'd get very far in life....
That's why, I've personally built myself a Second brain ( A digital notebook), to hold all the relevant information in my life with me, at all times!
That way when I access my digital notebook, I know exactly what I'm an expert on !